1. Preheat over to 180c. Grease and line the base and sides of a 30cm x 20cm tin with baking paper.
2. Sift flours, carb soda and cocoa into a large bowl. Make a well in the centre.
3. In a large jug, whisk together eggs, sugar, vanilla, oil and yoghurt. Add flour mixture and mix until smooth. Fold through the apple puree and raspberries.
4. Spoon mixture into prepared tin. Bake for 30 minutes or until a skewer comes out clean when inserted into the centre. Cool in tin for 5 minutes before turning out onto a wire rack to cool completely.
5. Cut into squares. Dust with icing sugar. Serve as a dessert with extra fresh berries and reduced fat ice-cream if desired.